My recent experiences have taught me that any call(s) that allegedly originate from 301 306-____ are, almost certainly some sort of scam.  Last month it was "reverse mortgages".  2 weeks ago it was "duct cleaning".  Lately they have "hopped on" the Medicare supplement scam.  Usually all it takes to get rid of these time-wasting bums is a good dose of my "intelligent cursing" (to quote President Truman).   Their employee turnover rates must be sky-high, so this new group hasn't yet realized that I'm not giving them any money.  They'll learn.